Papers by Keyword: Infrared Spectroscopy

Abstract: Nowadays, the material recycling is growing trend in development of building materials and therefore using of secondary raw materials for production of new building materials. Transition from application non-renewable sources of raw materials to renewable raw materials in terms of sustainable composite is required. Renewable raw materials include organic sources of raw materials coming from natural plant fibres. This material is used to contribute environmental protection and to save non-renewable resources of raw materials. Wood fibres and cellulose fibres made from waste paper were selected for reinforcing cement-based materials. Application of cellulosic fibres into composites depends on their properties. Therefore, this paper is aimed to study of morphology and properties of cellulosic fibres. The comparison of strength parameters of 28 days hardened composites with 5% adding bleached wood and unbleached recycled fibres with those of reference composite without fibres showed that the values of compressive strength of fibrous cement based specimens were lower by 17 to 29 %.

Abstract: This article deals with the study of direct current (DC), ultrasonic, and of electrolyte of the influence on the change of titanium dioxide sorption properties. The TiO₂ prepared by the TiCl₄ hydrolysis method. Attention is drawn to charging exchange processes the surface of titanium dioxide particles after they pass through a layer of counter ions in an aqueous medium under the influence of a DC. The stages of the end product’s formation using methods of the X-ray diffraction, the differential thermal and the infrared spectrometric and the gas adsorption analysis were proposed. Dependence of redistribution sorption active centers at the surface of TiO₂ was proved.

Abstract: The composition of the surface and electrical properties of silicon oxide nanocomposites of porous silicon were investigated by FTIR spectroscopy in the range of 400 – 4000 cm^-1 and by impedance spectroscopy in the frequency range of 25 Hz – 1 MHz. It was revealed the different dispersion of electrical capacitance in different frequency bands and the complex relaxation processes that affect the electrical transport properties of nanocomposites. The correlations between the IR absorption spectra of silicon oxide composites and processes of charge transfer was defined. On the basis of analysis of spectra of thermal stimulated depolarization it was shown that oxidation of the surface of porous silicon nanocrystals gives rise to changing the density of states in different energy ranges.

Abstract: Precise manipulation of nanoparticles (NPs) in rare earth doped inorganic glasses for achieving tuneable physical and optical properties is challenging. Series of erbium doped phosphate glasses containing ZnO NPs with composition (78.5-x)P₂O₅10Li₂O10ZnO1.5Er₂O₃(x)ZnO, where 0x1.2 are prepared using melt quenching method. The local structures analyzed using FTIR spectra reveal an increase in depolymerisation of the glass at Q₃ tetrahedral sites due to the introduction of ZnO NPs. The optical band gap energy obtained from UV-Vis absorption spectra varies within 3.533.59 eV and the Urbach energy increase as much as 0.260 eV. The role of ZnO NPs within the lithium (II) oxide-zinc oxide-phosphate glass matrix in influencing the optical and structural responses are analyzed and discussed. The observed optical improvements suggest that these glasses are potential for photonic devices.

Abstract: Based on structure and composition characteristics of engine oil, the new algorithm for its Infrared Spectrum (IR) Identification has been put forward. The Hit Quality Index and Related Hit Quality Index are widely used in Infrared Spectrum Identification recently. The two methods don’t take the importance of the variables into consideration and cannot distinguish the unobvious variation in IR spectra. Therefore the diversity weight factor was introduced into the new algorithm to promote its selectivity. The experimental results had shown that the new spectrum similarity evaluation index could distinguish the unobvious spectrum variations and to improve the infrared spectrum identification capability of engine oils.

Abstract: Styrene-Butadiene-Styrene (SBS) has been widely used in the modified asphalt engineering around the world due to its excellent contribution to both high and low temperature performance of asphalt. The content of SBS plays a critical role in the performance of modified asphalt. Therefore, an accurate and effective method to quantify the SBS content in modified asphalt was proposed based on the Fourier-Transform Infrared (FTIR) spectroscopy method. Two Infrared (IR) indices were provided to quantify the content of SBS. In addition, the practicability and accuracy of this method was verified by testing the prepared sample in laboratory.

Abstract: Optical parameters become to the features that are currently taken into account more frequently. There are various reasons of dealing with those parameters. Some of them are due to thermal calculation purposes while the other one are trying to consider low-emissivity functions of various innovative building materials. The paper is focused on spectral emissivity analysis of roof membranes and vapor barriers especially that are applied in sloped roofs and walls with air ventilated cavity. The spectral emissivity in the longwave radiation region was assessed by laboratory method of an infrared spectroscopy. The results present courses of spectral nature as well as its transformation into weighted values. As a result the final comparison demonstrates facts of aiming to point out the possibility of receiving any benefit for thermal aspects purpose.

Abstract: Factor group analysis on the deformed pyrochlore-structure hydroxyl transition metal halides M₂(OH)₃X (M = Co, Fe and Mn; X = Cl, Br and I) with the crystal symmetry ≡ D_3d⁵ of space group No. 166 for their infrared (IR) and Raman spectroscopic studies are, for the fist time to the best of our knowledge, reported. Through a standard factor group analysis, we predict that there are 17 IR active normal modes (7A_2u+ 10E_u) and 12 Raman active modes (5A_1g + 7E_g), caused by five atomic site groups [HOM₃], [OM₃], [MO₄X₂], [ClM₃] and [MO₆], where the black body letters represent the site atoms. In addition we figure out all the atomic displacement patterns of 12 Raman active normal modes, and point out these results are completely same as those of the famous geometric frustration material Herbertsmithite ZnCu₃(OH)₆C_l2.

Abstract: Determination of TiOCl₂ in refined TiCl₄ was significant for analysis of its impurities. TiOCl₂ could be determined by infrared spectroscopy due to its infrared characteristic spectrum line. However, normal infrared absorption cell was not fit for the sample analysis, because TiCl₄ easily reacted with moisture in the air and immediately was hydrolyzed to form highly corrosive hydrochloric acid smoke. The infrared absorption cell with the window film of ZnSe ( Ф10×1mm, wavenumbers: 7800cm^-1~440cm^-1) and the glass cell (optical path: 22mm, 12mm, 7mm and 4mm) was assembled and utilized in determination of the TiOCl₂ in refined TiCl₄ by standard addition method. The detection limit of TiOCl₂ was 26.5mg•kg^-1, the regression equation was Y=1.0118X, R²=0.9926; With standard addition method, the regression equation of TiOCl₂ was Y=1.9400X, R²=0.9940,This infrared absorption device was safe, simple and convenient, easily removable and washable, and re-useable. This method could meet the requirement of determination of TiOCl₂ in refined TiCl₄.

Abstract: Geopolymers are inorganic materials having interesting properties for many using areas. It is well known that geopolymers present various properties depending on the aluminosilicate sources used but lack of understanding are effective. This study consists on the comprehension of the formation of different networks in geopolymers by modify the reactivity of siliceous species in the reactive mixture with ammonium molybdate. These experiments evidenced the existence of various polycondensation reactions between materials leading to the formation of different networks. Moreover the use of ammonium molybdate addition in the mixture induces a slowdown of the reaction.